Nudger force preload adjustment

ABSTRACT

A device for moving a sheet of media in a device or machine for handling stacks of media is provided. The device includes a roll, an arm, and a bias element. The roll may be in contact with the sheet of media. The arm may be coupled to the roll. The bias element has a first end and a second end. Either the first end of the bias element is adjustably coupled to the arm or the second end of the bias element is adjustably coupled to the body. The body supports the bias element. The first end of the bias element may be coupled to the arm and the second end may be capable of adjustably coupling with the body in at least two positions (e.g., two or more of a nominal load setting, a reduced load setting, and an increased load setting).

BACKGROUND

This disclosure generally relates to any machine or device for handling stacks of media, such as reprographic machines (or other image marking technologies), finishing devices (not producing an image), document handlers (for scanning original documents) or other media handlers, and specifically relates to media handling, such as feeding, transport and finishing of media (e.g., paper and other stock).

Sheets of paper (or other media) are typically fed one sheet at a time to a machine from a stack of media in an input tray. A sheet is nudged or moved off the top of the stack and onto a path for media handling. In order to nudge the sheet off of the top of the stack, one or more cylindrical rollers (or nudger rolls) rotate in contact with the sheet on the top of the stack, applying a force (i.e., a nudger force) to move the sheet in the direction of the path.

SUMMARY

During manufacture, an initial tolerance is set for an assembly associated with the cylindrical rollers. Tolerance has to do with total permissible variations of size. Over time, the tolerance may no longer be effective for various reasons, such as wear or a change in media. As machines age, typically the cylindrical rollers wear and reduce slightly in diameter thus drifting from nominal tolerances; it is also possible due to contamination that the coefficient of friction on the surface of the cylindrical rollers changes, resulting in a shift in performance. When the tolerance changes, the nudger force exerted by the cylindrical rollers changes, and two errors commonly occur. The first error is misfeeding, which occurs when the cylindrical rollers are not able to force the sheet off of the top of the stack. The second error is multi-feeding, which occurs when the cylindrical rollers move multiple sheets at once, typically causing a jam.

One exemplary embodiment is a device for moving a sheet of media in a machine. The device may include a roll, an arm, and a bias element. The roll may be in contact with the sheet of media. The arm may be coupled to the roll. The bias element has a first end and a second end. The first end of the bias element is adjustably coupled to the arm and/or the second end of the bias element is adjustably coupled to the body. The body supports the bias element. The first end of the bias element may be coupled to the arm and the second end may be capable of adjustably coupling with the body in at least two positions (e.g., two or more of a nominal load setting, a reduced load setting, and an increased load setting). The first end may be adjustably coupled with the arm in one of at least two positions (e.g., two or more of a nominal load setting, a reduced load setting, and an increased load setting) and the second end may be fixed to the body. The body may have castellations or detent features and the second end of the bias element may be adjustably coupled to the body at one of the castellations or detent features. The body may have a removed or removable component for preventing adjustment of the coupling of the second end of the bias element. The device may also include a retainer to retain the removed component in the machine. The device may also include a drive shaft, a motor coupled to the drive shaft, and a drive belt coupled to the drive shaft and the arm of the device.

Another exemplary embodiment is a method of manufacturing a device for moving a sheet of media in a machine. A roll is provided and an arm is coupled to the roll. A body is provided and a bias element is adjustably coupled to the body and/or arm. The bias element has a first and a second end. The first end of the bias element may be adjustably coupled to the arm or the second end of the bias element with the body in one of at least two positions (e.g., two or more of a nominal load setting, a reduced load setting, and an increased load setting). The first end may be adjustably coupled with the arm in one of at least two positions (e.g., two or more of a nominal load setting, a reduced load setting, and an increased load setting) and the second end may be fixed to the body. The body may have castellations or detent features and the second end of the bias element may be coupled to one of the castellations or detent features. The body may have a removable component for preventing adjustment in the coupling of the second end of the bias element with the removable component.

Yet another exemplary embodiment is a method for moving a sheet of media in a device. Pressure is applied to the media to move the media. The pressure to the media is adjusted based on predetermined media parameters. Optionally, the pressure may be adjusted to the media based on operating parameters of the device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an exemplary embodiment of a preload adjustment mechanism having a factory set default setting;

FIG. 1B illustrates the exemplary embodiment of the nudger preload adjustment mechanism of FIG. 1A having a higher nudger force setting than in FIG. 1A;

FIG. 1C illustrates the exemplary embodiment of the nudger preload adjustment mechanism of FIG. 1A having a lower nudger force setting than in FIG. 1A;

FIG. 2A illustrates another exemplary embodiment of a nudger preload adjustment mechanism having a nominal load setting;

FIG. 2B illustrates the exemplary embodiment of the nudger preload adjustment mechanism of FIG. 2A having an increased load setting;

FIG. 2C illustrates the exemplary embodiment of the nudger preload adjustment mechanism of FIG. 2A having a reduced load setting;

FIG. 3A illustrates another exemplary embodiment of a nudger preload adjustment mechanism having a nominal load setting;

FIG. 3B illustrates the exemplary embodiment of the nudger preload adjustment mechanism of FIG. 3A having a reduced load setting;

FIG. 3C illustrates the exemplary embodiment of the nudger preload adjustment mechanism of FIG. 3A having an increased load setting;

FIG. 3D illustrates another exemplary embodiment of a nudger preload adjustment mechanism;

FIG. 4 illustrates typical locations of an exemplary embodiment of a nudger roll assembly in a machine; and

FIG. 5 illustrates an exemplary embodiment of a nudger roll assembly.

EMBODIMENTS

Exemplary embodiments include a device for moving media in a device having a roll and an adjustable pressure control device.

Exemplary embodiments include devices and methods to effect a nudger force preload adjustment. A nudger force is a force applied by one or more cylindrical rollers (or nudger roll) that nudges (or moves) a sheet off the top of a stack in an input tray and moves the sheet in the direction of an input path of a machine, such as a printer or copier. The nudger roll is typically part of an assembly including a bias element (e.g., pressure device, compression spring or torsion spring). The bias element is coupled to the nudger roll. When installed, the bias element is compressed or preloaded. The preload length is the distance the bias element is compressed from its free length. The preload force may be adjusted by changing the preload length. A preload force is the initial force the bias element exerts when extended. Increasing the preload length, increases the preload force exerted by the bias element. The preload force governs the nudger force by effecting its magnitude. That is, an increase (or decrease) in the preload force increases (or decreases) the nudger force.

Exemplary embodiments enable the nudger force preload adjustment to be performed in a controlled and incremental manner in the field, when the default settings no longer are adequate. A default setting at a predetermined nominal preload may be maintained with an anti-tampering device, such as a removable component. The anti-tampering device minimizes customer tampering, which is desirable because an unneeded or incorrect nudger force preload adjustment may actually induce misfeeding or multifeeding errors. When it is determined that adjustment is necessary, the anti-tampering device may be inactivated and the appropriate adjustment to the bias element governing the nudger force may then be made.

FIGS. 1A, 1B, and 1C illustrate an exemplary embodiment of a nudger preload adjustment mechanism 100 having a default setting. In FIG. 1A, the nudger preload adjustment mechanism 100 includes a bias element 102, which has an arm 104 set in a default position of a member 106. The bias element 102 may be a coil, a helical compression or a tension spring, a torsion spring, or any other kind of bias element 102.

The member 106 may be any body or plate having adjustment levels 108, such as castellations, slots, notches or anything else capable of receiving and holding the arm 104 of the bias element 102 in different positions. The member 106 may have any number of adjustment levels 108, including the default position. The default position may be a neutral or nominal preload setting that is set during manufacturing. The adjustment levels may be based on engineering testing and development, predetermined media parameters, and operating parameters of particular machines. Only two adjustment levels (i.e., one level up and one level down) have been illustrated in FIG. 1 for clarity. However any number levels of adjustment in either the up or down direction may be included in the member 106. A larger number of adjustment levels 108 provide a finer adjustment, while a smaller number of adjustment levels 108 provide a coarser adjustment. The number of higher adjustments may be different than the number of lower adjustments. The member 106 shown in FIG. 1 is a rectangular plate, but exemplary embodiments may have varying shapes.

FIG. 1B illustrates the exemplary embodiment of the nudger preload adjustment mechanism 100 having an increased or higher (“+”) nudger force setting than in FIG. 1A. That is, the setting shown in FIG. 1B causes an increased preload force, which results in an increased or higher nudger force applied to a sheet on the top of the stack of an input tray to nudge or lift and move the sheet onto an input path of the machine.

An anti-tampering device 110 or other removable component may be removed, opened, snapped out, or otherwise disabled in order to adjust the nudger force setting to an increased (or decreased) nudger force setting. Typically, a service person makes the nudger force preload adjustment. The anti-tampering device 110 reduces the likelihood of unwanted tampering by customers in the majority of machines that do not experience problems or require adjustment. Such customer tampering could actually induce problems, such as misfeeding, multi-feeding and jamming. The anti-tampering device 110 may be optional. The anti-tampering device 110 may be designed so that it may be freed yet retained to prevent the anti-tampering device 110 from falling off into the machine or becoming lost. The anti-tampering device may be a removable component that may be retained or otherwise attached to the device or other body. The anti-tampering device may be moved or removed to define an opening to allow for manipulation of the bias element, such as, for example, adjusting the coupling of the bias element at the arm and/or the body of the device.

FIG. 1C illustrates the exemplary embodiment of the nudger preload adjustment mechanism of FIG. 1A having a lower (“−”) nudger force setting than the default setting in FIG. 1A. A field service manual may instruct service personnel how to make the adjustment based on various observable problems. Because the adjustment may need to be precise to impart the correct amount of preload force, predetermined adjustment levels 108 eliminate guesswork and avoid possible permanent and irrecoverable mechanical damage to the bias element 102 or other parts.

FIGS. 1A, 1B and 1C illustrate a general concept of indexed loading. The nudger preload adjustment mechanism 100 may be used to increase or decreased the load on the bias element 102 according to predefined adjustment levels 108 (or indexes). The preload force, in turn and the nudger force, are indexed into adjustment levels, such as nominal or default (FIG. 1A), higher or increased (FIG. 1B) and lower or decreased (FIG. 1C). The indexed loading may be performed in various ways and with various mechanical devices.

The bias element 102 may exert the preload force on a carrier (not shown) for a nudger roll (not shown). The carrier may be or include the member 106 or the carrier may be coupled to the free end of bias element 102. The carrier may be an arm that is restrained by a pivot with active rotation around a shaft with the nudger roll on the end of the shaft. The nudger roll may be driven mechanically, typically by either a belt drive or a gear train.

FIG. 2A illustrates another exemplary embodiment of a nudger preload adjustment mechanism 200 having a default or nominal load setting. The nudger preload adjustment mechanism 200 includes a nudger roll 202 coupled to a nudger roll arm 204. A bias element 206 is coupled to the nudger roll arm 204 and a nudger body 208. The nudger roll 202 imparts a force to the media 210. The nominal (“0”) load setting is a predetermined distance 212 from the axis of the nudger roll 214.

The nudger roll 202 is a cylindrical roller that contacts a sheet of media 210 at the top of a stack of media in an input tray in order to nudge or lift and move the sheet onto an input path for the machine. The nudger preload adjustment mechanism 200 may include more than one nudger roll 202, such as a pair of nudger rolls 202. The nudger roll 202 may also be coupled to a device that imparts a rotational velocity to the nudger roll 202. The nudger roll 202 in FIG. 2A exerts a nudger force on the media 210 in a direction and of a magnitude that is neutral or nominal for nudging the media 210 without causing misfeeding or multifeeding errors under normal conditions, such as just manufactured machines. The nudger roll may impart a normal force onto the media 210 by virtue of the bias element 206 acting through the fixed arm length of the nudger roll arm 204.

The bias element 206 is any kind of element capable of exerting a force on the nudger roll arm 204 under indexed loaded conditions, such as a coil, helical, compression, tension, leaf or torsion spring. The bias element in FIG. 2A is coupled to the nudger roll arm 204 and the nudger body 208 in such a way that the predetermined distance 212 from the axis of the nudger roll 214 to the center of the bias element 206 is a nominal (or default) setting for the nudger preload adjustment mechanism 200. The bias element 206 may be coupled to the nudger roll arm 204 and the nudger body 208 in many ways.

The nudger body 208 is coupled to one end of the bias element 206, while the other end of the bias element 206 is coupled to the nudger roll arm 204. The nudger body may be any rigid body capable of coupling to the bias element 206 under indexed load conditions. The nudger body 208 may also be coupled to the nudger roll arm 204. The nudger body 208 may incorporate a variety of methods of indexing the predetermined distance 212, such as multiple screw holes with only one screw position, detent features with a slotted screw hole, and many other methods of indexed loading.

The point of articulation of the nudger roll arm 204 may be raised (FIG. 2B) or lowered (FIG. 2C) from the nominal setting (“0”) of FIG. 2A with respect to the axis of the nudger roll 214 through indexed loading, thus increasing (FIG. 2B) or decreasing (FIG. 2C) the ability of the bias element 206 to impart the nudger force onto the media 210. FIG. 2B illustrates the exemplary embodiment of the nudger preload adjustment mechanism 200 of FIG. 2A having an increased (“−”) load setting, which is a predetermined distance 216 from the axis of the nudger roll 214. FIG. 2C illustrates the exemplary embodiment of the nudger preload adjustment mechanism of FIG. 2A having a reduced (“−”) load setting, which is a predetermined distance 218 from the axis of the nudger roll 214.

FIGS. 3A-3C illustrates another exemplary embodiment of a nudger preload adjustment mechanism 300 having a nominal (“0”) load setting (FIG. 3A), a reduced (“−”) load setting (FIG. 3B) and an increased (“+”) load setting (FIG. 3C). Instead of changing the position of the nudger body 208 (as in FIGS. 2A-2C), the position of the bias element 304 may be indexed through one of three, one of six, ten or any number of holes in different directions, depending on the desired preload. The nudger roll 202 imparts a normal force onto the media 210 by virtue of a bias element 304 acting through a fixed arm 302 length. By changing the point at which the bias element 304 acts on the arm 302, the ability of the bias element 304 to impart load is increased or decreased.

FIG. 3D illustrates another exemplary embodiment of a nudger preload adjustment mechanism 300. This embodiment achieves indexed loading by changing the point at which the bias element 308 acts on the nudger body 310. In other words, the nudger body 310 is indexed (“+”, “0”, “−”) in FIG. 3D as opposed to the arm 302 being, indexed as in FIGS. 3A-3C. Other embodiments may achieve indexed loading in other ways.

FIG. 4 illustrates typical locations of an exemplary embodiment of a nudger roll assembly in a machine 400. Exemplary embodiments of the nudger roll assembly may be located in many places, such as the following typical locations: duplex automated document handler 402, multi-sheet inserted 404, high capacity feeder 406 and paper trays 408. Other embodiments may include nudger roll assemblies in various other places and locations. A nudger roll assembly includes a nudger preload adjustment mechanism 200, 300 as well as additional elements, as illustrated in FIG. 5.

FIG. 5 illustrates an exemplary embodiment of a nudger roll assembly 500. FIG. 5 illustrates the nudger roll assembly 500 in an upside down orientation in order to better show the elements. However, the nudger roll assembly 500 is illustrated upside down from its usual orientation in a machine. A sheet of media passes over the top of the nudger rolls 502 as shown in FIG. 5, while typically a sheet of media passes under nudger rolls 502 in a machine. That is, the nudger roll assembly 500 is placed in a machine so that the nudger rolls are on top of the stack of media (upside down from that shown in FIG. 5).

FIG. 5 shows a pair of nudger rolls 502, which operate similarly to a single roll. The pair of nudger rolls 502 come into contact with a sheet on the top of a stack of media in an input tray. A rotating guide arm 504 is coupled to the nudger rolls 502 to impart a rotational velocity to the nudger rolls 502. A drive motor 506, drive shaft 508, and drive belt 510 drive the nudger rolls 502. The take away rolls 512 form a nip that pulls the sheet nudged by the nudger rolls 502 and move the sheet onto an input path in the machine for printing, copying, or other processing. The nudger roll assembly 500 may include additional elements.

It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, and are also intended to be encompassed by the following claims. 

1. A device for moving a sheet of media in a machine, comprising: a roll capable of contacting the sheet of media; an arm coupled to the roll; a bias element having a first end and a second end, the first end of the bias element being adjustably coupled to the arm and/or the second end of the bias element being adjustably coupled to the body; and a body supporting the bias element.
 2. The device of claim 1, wherein the first end of the bias element is coupled to the arm and the second end is capable of adjustably coupling with the body in at least two positions.
 3. The device of claim 2, wherein the at least two positions are two or more of a nominal load setting, a reduced load setting, and an increased load setting.
 4. The device of claim 1, wherein the first end is adjustably coupled with the arm in one of at least two positions and the second end is fixed to the body.
 5. The device of claim 4, wherein the at least two positions are two or more of a nominal load setting, a reduced load setting, and an increased load setting.
 6. The device of claim 1, wherein the body has castellations and the second end of the bias element is adjustably coupled to the body at one of the castellations.
 7. The device of claim 1, wherein the body has detent features and the second end of the bias element is adjustably coupled to the body at one of the detent features.
 8. The device of claim 1, wherein the body has a removable component for preventing adjustment of the coupling of the second end of the bias element.
 9. The device of claim 8, wherein the component is removed from the body.
 10. The device of claim 9, further comprising: a retainer to retain the removed component in the machine.
 11. The device of claim 1, further comprising: a drive shaft; a motor coupled to the drive shaft; and a drive belt coupled to the drive shaft and the arm of the device.
 12. A method of manufacturing a device for moving a sheet of media in a machine, comprising: providing a roll; coupling an arm to the roll; providing a body; adjustably coupling a bias element to the body and/or arm.
 13. The method of claim 12, the bias element having a first and a second end, the method further comprising: adjustably coupling the first end of the bias element to the arm or adjustably coupling the second end of the bias element with the body in one of at least two positions.
 14. The method of claim 13, wherein the at least two positions are two or more of a nominal load setting, a reduced load setting, and an increased load setting.
 15. The method of claim 13, further comprising: adjustably coupling the first end with the arm in one of at least two positions; and fixing the second end to the body.
 16. The method of claim 15, wherein the at least two positions are two or more of a nominal load setting, a reduced load setting, and an increased load setting.
 17. The method of claim 13, the body having castellations, the method further comprising: coupling the second end of the bias element to one of the castellations.
 18. The method of claim 13, the body having detent features, the method further comprising: coupling to the second end of the bias element to one of the detent features.
 19. The method of claim 13, the body having a removable component, the method further comprising: preventing adjustment in the coupling of the second end of the bias element with the removable component.
 20. A method for moving a sheet of media in a device, comprising: applying pressure to the media to move the media; adjusting the pressure to the media based on predetermined media parameters; and optionally adjusting the pressure to the media based on operating parameters of the device. 